In the semiconductor industry, devices are fabricated by a number of manufacturing processes producing structures of an ever-decreasing size. Some manufacturing processes such as plasma etch and plasma clean processes expose a substrate to a high-speed stream of plasma to etch or clean the substrate. The plasma may be highly corrosive, and may corrode processing chambers and other surfaces that are exposed to the plasma. This corrosion may generate particles, which frequently contaminate the substrate that is being processed, contributing to device defects.
As device geometries shrink, susceptibility to defects increases and particle contaminant thresholds become more stringent. Accordingly, as device geometries shrink, allowable levels of particle contamination may be reduced. To minimize particle contamination introduced by plasma etch and/or plasma clean processes, chamber materials have been developed that are resistant to plasmas. Typically, chamber components are coated with plasma resistant coatings using plasma spray processes. The plasma sprayed coatings have a porosity of about 2-7% and many micro-cracks. Additionally, the plasma sprayed coatings generally have a high surface roughness of about 200-250 μ-inch, which may cause loose particles to get trapped in crevices of the plasma resistant coating. As a result, the plasma sprayed coatings often shed particles after plasma bombardment, which can reduce yield of manufactured devices.